Recent rise of silicon audio players and hard disk music players of portable types allows several hundreds to several tens of thousands of music pieces (music content) to be recorded in a recording medium in one playback apparatus to play back the recorded music pieces. It has been possible for users to carry preferred music pieces recorded in their own players and to listen to the recorded music pieces that are played back at any time.
Recording many music pieces in recording media to make the music pieces to be played back enables users to enjoy listening to the music for a long time. In addition, so-called shuffle playback in which the order of music pieces to be played back is changed at random allows users to listen to the music pieces in an unexpected order, so that the users are not bored with the music pieces. However, such audio players only play back the music pieces recorded in advance, and the same sound is played back every time in terms of each music piece although the number of the music pieces is increased.
Computer software, such as automatic music composition software (automatic music composition programs), is also known. With such computer software, it is sufficient for users to input situations, for example, the atmospheres of music pieces or their birthdays, in order to compose music pieces. For example, Japanese Unexamined Patent Application Publication No. 2002-117069 discloses a method of generating an appropriate music sequence (sequence of audio data) of an arbitrary length from music items (audio data to be used as materials) in a database.
Users can use such automatic music composition software through personal computers to easily and freely create original audio content and to enjoy listening to the audio content that is played back.
However, since the above automatic music composition software only generates a note for every tone or only combines materials determined in advance, it is difficult to compose high-quality music pieces (audio content) about which many audiences feel “excellent”. In addition, since it is complicated or difficult to operate the automatic music composition software invoked in personal computers, it is difficult for users unfamiliar with the personal computers to use the automatic music composition software.
Most automatic composition software uses Musical Instrument Digital Interface (MIDI) data for music composition and, therefore, there are restrictions in the automatic music composition software. For example, tones of musical instruments lack the reality or natural voices of human beings cannot be played back in the case of the automatic music composition software. Even if the reality is increased, the music pieces composed by the automatic music composition software often make no impression on users when the users know that the music pieces are not played by human beings.
Accordingly, it is an object of the present invention to provide an apparatus and a method, which are capable of using audio content data as materials in various modes to easily create a new high-quality audio content.